Conventional vehicles such as one disclosed in Patent Literature 1 has adopted a structure for protecting an occupant in a front impact of the vehicle, the structure including an axially compressively deformable crash can disposed at a front end of a front side frame made of a high tensile strength steel, and allowing the front side frame to actively deform to bend from an intermediate portion to a rear end thereof.
In such a structure, most of an impact load is absorbed by the bending deformation of the front side frame. Therefore, the energy absorption characteristic of the bending deformation has a greater influence on EA (Energy Absorption) efficiency, i.e. the energy absorption amount per unit mass, than the energy absorption characteristic of the compressive deformation.
Here, it is necessary to further improve the EA efficiency in order to expand design options of a vehicle body and reduce the weight of the vehicle body.